Process for the production of azo dyestuffs and azo dyestuffs obtainable thereby



Patented Dec. 23, 1930 ,UNITED STATES PATENT OFFICE 'nIcHAnn sruns'snn, or COLOGNE-ON-THE-RHINE,GERMANY, ASSIGNOR '.110 GENERAL 'ANILINE WORKS, me, or new YORK, N; Y., A CORPORATION or DELAWARE,

' rnoonssron THE Pnoioucrron' oF-Azo DYESTUFFS AND Azo DYESTUFFS OBTAINABLE THEREBY No Drawing. Application filed'i'uly 11, 1927, Serial No. 205,041, and in Germany July 29,1926.

This invention relates to a process for the production of, azo dyestuffs, and to new azo dyestuffs obtainable thereby.

It. has been found that valuable azo dyestu'lfshaving the general formula R--N=N-QXC N=NR f o j coon nooc wherein Rrepresents the residue of anycoupling component COIItZLIIIIIIg III ortho-posltion to the azo group a substituent of the group comprising amino, arylamino, acylamino, hydroxyl and the desmotropic .keto group; and X represents one of the groups azoxy and azo, may be obtained by subjecting 2 molecular proportions of dyestuffs having the, generalformula f v coon wherein R represents any coupling component containing an auxochrome group, to careful reduction with alkaline reduction -means, such as, for example, reduction by means of grape sugar and alkaline acting agents, particularly caustic .soda solution.

When proceedingin this way there are obtained at first the azoxy compounds and then by enhancing the reducingv action the corresponding azo compounds. It has been ascertained that the azo compounds generally possess a deeper coloration than the corresponding azoxy compounds and that the reduction process can be controlled by watching the coloration of the reaction mixture. In many cases, however, the reduction-process cannot be controlled exactly and the reaction products in these cases represent mixtures of the .azoxy compounds: and the corresponding azocompounds. The formulae of the reaction products obtainable according to the examples described hereafter have. been ascertained as far as possible. However, in view of the above, it is to be understood that all these reaction products may represent partial mixtures.

" The coupling components, represented by the reference character R in the above general formulae, may be any suitableauxochrome group-containing intermediates such as, for instance, naphthol sulfonic acids, naphthlyamine sulfonic acic s, phenol, aromatic amines, aromatic diamines, pyrazolons and aceto-acetic arylides, containing therein sulfonic, or carboxylic, acid groups, or, as in the case where the reference character X in the above general formula represents the azo group, the coupling componentsmay be monoazo-, or polyazo-, dyestuffs.

The new dis-, and poly-, azo dyestuffs, obtained by practicing the process according to the present invention, are generally soluhis in water with a yellowish to bluish-black coloration, soluble in concentrated sulfuric acid with a yellowish to bluish coloration, and dye cotton orange to blue to black shades whichmay be rendered fast to washing and .to light by after-,treatmentwith heavy metal salts such as, for example, salts of copper,

chromium and cobalt. lVhen subjected to reduction with stannous chloride and hydrochloric acid, l molecule of the new dyestuif yields 2 molecules of l/i-phenylenediamine carboxylic acid and 2 molecules of an aromatic amine; in those cases where the reference character in the above general formulacrepresents an axe dyestuff, the azo groups also may be reduced, as well as any intro-groups when present. If acetylaminogroups are present'in the dyestuffs, the reduction with stannous chloride and hydrochloric acid convercls them into amino compounds and acetic ac1 The present invention may be illustrated by the following examples:

Emample 1 about 50 C. until the reduction of the nitro groups to azoxy or azo has been finished. In the case of reduction to azo, the resulting diaminoazo -dyestulf product, having most probably the formula:

OOzNa. COzNa is freedfroin salt andiiltered {itis then tetra- Zotizedin the] known manner and coupled with 330 parts by weight of 2.4 dia1ninoacetanili'd. The resulting dye'stuif, having most probably the forrnula: s

' i NH;

is,s wilien driedand pulyerized, a black pow dersolu'b'lein waterand in concentrated sul- V furi'c acidwitha-blue' coloration, the sulfuric tion with grape sugar at G.- into the azoxy or azo compound,respectively, and the acidsolution when poured into water bGlBODl ing yi-oflet'." It dye's cotton black'shades which are renderedflfast to washing and to light by after-treatnieritwith chromium salts.

Example 2 182 parts'by' Weight of 5fnitro-2-an1inobenzoic acid are diazotized, as above, and coupled with 239parts by weight of 2-an inov 5 hydroxynaphthalene -7- -.sulphonic acidf 'Then,{ the nitro group resulting from the lnonoazo dyestuff is reduced in alkaline solu- .7

trisaz oedyestuif, or disaZooXy-dyestufl', respectlvely, is freed from the reaction mixture in the known manner. It is, when dried and pulverized,-a-blacl powder which dyes cot- 1 formula iton iolet shades.

It has most probably the or: coma coma H:N SOaNa I I The, dyestuff can bepfurther diazotized on the fiber and coupledwith the well known developers and resulting dyeings can be subjected to after-treatment with chromium salts. *For instance, coupled in this manner with ,B-naphthOl and subjected to after-treatment with copper sulfate, a fast black-blue I shade is obtained.

I 7 Emample 3 182 parts by weight of 5-nitro.-2+aminoformula OO Na benZoic acid are diazotized a-nd coupled, in thewell known manner, with 315 parts by O Q- m e ght o -PhGHflin fi-by ynaph- -'th'alene-7-sulfonic acid, then 1500 parts by Weight of 38 B. caustic soda solution and 175 parts by'weight of-igrape sugar are put into the coupling liquorand heated to about COzNa NH:

C. until the aZo-dyestuif has separated in crystal form. The dyestuffis, when dried 1 and ground, a black powder soluble in hot water and in concentrated sulfuric acid with bluish-red coloration. When the sulfuric acid solution is vpouredinto water, vit-becomes bluish-violet: The dyestufif yields on cotton violet shades. which, by" after-treat: ment with copper chloride,1are changed into a clear blue which isfast against washing and light-elfects. lt hasrnost probably 'the' 182 parts weight of 5-nitro-i2-arnino-g.

of thev dyestuif product colors cotton well. The resulting dyestuif' product is separated in known'inanner. Itisa black powder which yields on cotton shade's"similar to {inoenzoic acidj-are di zotized, imtheijknown solution, with 306 parts by weight of 1- ,B-naph- .1 thyl-3-methyl-5-pyazolon-6-sulfonic a c i d,

'whereupon'2500 parts by weight of 38 Be. caustic soda solutionand 17 5 parts by weight of grape sugar are added and the mixture is heated until a sample of the resulting dyestuff colors cotton, well. The dyestuff is, then, freed from salts, filtered and dried. In its free state it has the probable formula COOH It is. a brown powderrwhich yields on cottons orange shades'which are changed to brick-red shades of good fastness by after- 7 treatment with copper salts. 7

Example 6 i Two molecular proportions of the dyestufi' with 1 molecular proportion of the diazoare carefully reduced by heating, at a tem- I alkaline acting medium.

compound of 5-n1tro-2-amino-benzoic acid perature above normal room temperature, say about 40 G.,,with grape sugar in an The reduction product, when freed from the reaction mix- 7 tion. It dyes cotton bluish violet shades a ture in the known manner, is a dyestuff having most probably the formula It is soluble in water and in concentrat-' ed sulfuric acid with a bluish-red coloration; the sulfuric acid 7 solution when poured into water assuming a bluish colorawhich, upon after-treatment with copper salts, are converted to blue shades of good fastness properties with respect to washing and to light. Reduction of 1 molecule of the dyestuif with stannous chloride and hydrochloric acid yields 2 molecules of phenylenediamine-carboxylic acid and 2 molecules of Q-amino-S-diethylamino-l-naphthol- 3-sulfonic acid.

I claim 1. As new products, azo dyestuffs having the general formula coon I coon OOONa.

Naols wherein R represents the residue of any coupling component containing" in orthoamino, hydroxyl and the desmotropic keto group, and X represents one of the groups azoxy and azo, which dyestuffs are generally soluble in water and in concentrated sulfuric acid,'and yield on cottonorangeto blue to black shades which may be rendered fast to COOH . N \C=OJ I. e "zgmk' I u a I washing and to light by after-treatment with heavy metal salts.

2. As new products, azo dyestuflt's'having the general formula R'-1 I=N'Ox wherein X represents one of the groups azoxy and azo, and wherein R represents the heavy metal salts.

/C)H| ClH| 3. As new products, azo dyestuffs having the general formula C O OH O OH acid, and yield on cotton orange to blue to black shades which may be rendered fast to washing and to light by after-treatment with heavy metal salts.

4. As new products, azo dyestuffs having the general formula residue of any coupling component being sub- 7 stituted'in ortho-position to the azo group by 7 ing most. probably the formula wherein X- repre sents one of the groups azoxyand azo and R represents a residue of u can a-napthol-fi-sulfonic acid substituted by a group; containing a tervalent notrogen atomwhich is not directly joined to anoxygen atom, which dyestuffs are' generally eoluble in water and iii concentrated sulfuric acid, and, yield on cotton orange to-blue to black-shades which may be rendered fastto washingvand to light by after treatmentwith heavy metal salts. c

5. As a new product, the azo dyestufl hav- CORE 002B, NHg

Nrtooolai I o v which dyestufi is, in the dried and pulverized state, a black powder soluble in water and in concentrated sulfuric acid with a blue col'oration, eolublein dilute sulfuricnacid with a violet coloration, and yielding on cotton black V dyeings which are rendered "fast to washing V and to light by after-treatment with chrom- Y ium salts. I v I Q v Iii testimonywhereofi, Iaflix mygsignatureb I j RICHARD. STUESSER; 

